Chair arm



FIG. 1 is a perspective view showing the front, right side and top of a chair arm which forms my new design, the broken lines of chair arm features in this and other figures being for illustrative purposes only and forming no part of my design;

FIG. 2 is a right side elevational view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a front elevational view thereof;

FIG. 5 is a rear elevational view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof. 

The ornamental design for a chair arm, as shown and described. 